1. Technical Field
The present invention relates to a method of aligning a wafer and an alignment apparatus using the method, and more particularly, to a method of aligning a wafer which can prevent a defect from occurring during processing a wafer due to a recognition error by improving a recognition rate of the equipment, and to an alignment apparatus using the method.
2. Description of the Related Art
In general, a wafer may be cut into a plurality of semiconductor chips using a sawing apparatus that uses a blade or a laser beam. The wafer accommodated on a wafer chuck table of the sawing apparatus may be recognized using a camera installed in the sawing apparatus. The sawing apparatus also includes an alignment apparatus for aligning a reference line of the wafer with an alignment line of the wafer chuck table by reading an image.
A conventional alignment apparatus generally employs a method of producing the center line of a wafer by recognizing a ball or line formed on a surface of the wafer using a camera. However, according to the conventional wafer alignment method, when the ball or line formed on the surface of the wafer is deformed, a recognition error may be generated so that a sawing defect may be generated. Furthermore, as a resin layer is coated on the surface of the wafer to protect the surface of the wafer, the camera may have difficulty recognizing an align key or a pattern such as the ball or line on the surface of the wafer so the wafer may not be aligned.